Category Archives: environment

The Kansas Palmer Drought Severity Index, Unit Roots, and Snakes in a Room

In my post on modeling the Kansas economy, Rick Stryker takes me to task for modeling the Palmer Drought Severity Index (PDSI) for Kansas as an I(1) process:

I wouldn’t bother with the ADF test, since its null is non-stationarity and it has low power to reject. I would focus on the KPSS, since its null of stationarity is almost certainly what’s really true.

Continue reading

Global Temperature Anomaly, Through September

globanom_sep16

Source: NOAA

The highest point estimate for the anomaly is for 2016. For 2014, the 95% interval is ±0.09°C [1]. If that is ballpark for the 9 months estimate, then one can’t say that 2016 is hotter than 2015 (with statistical significance at the 5% msl), but can say it is hotter than 1998, a year often focused on by the “hiatus”-ers.

Update, 5:08PM Pacific: Here is a trailing 60 month moving average, ending observation for September 2016.

globanom_sep16_60momovav

Source: NOAA